Many applications exist which require a need to efficiently deliver a fluid to a local area of a surface, or region in space, that is selected at random. Yet, in most cases, this fluid is delivered by flooding the area, or region, of interest with the fluid and, thereby, eventually providing the required coverage. Unfortunately, this results in uneven levels of fluid deposition or concentration levels in some regions and insufficient deposition or concentration levels in others. This proves to be inefficient, wasteful, and in some applications, results in the unnecessary spread of dangerous or toxic products. Applications may simply involve the watering of grass and plants in a suburban home, spraying of deicing chemicals on the wings of aircraft at the local airport, insecticide spraying on a farm, the injection of fire suppressants in an attempt to extinguish a fire or the process of thermal cooling of electrical and electronic components to prevent overheating, such as those found in telecommunication and computer spaces.
Although there are some complicated mechanical mechanisms which may be capable of moving or articulating a fluid nozzle to an area of interest, these devices tend to be bulky and have many operational problems. Further, while these devices may possibly incorporate some limited feedback, there is no real time intelligence integrated into the device or the ability to evaluate the local conditions to ascertain when enough fluid has been delivered in real time. In some applications, the time response is critical to the effectiveness of the fluid delivery system.
The potential for accidental or intentional ignition in, or around, aircraft dry bays and engine nacelles remains a high-level threat to commercial and military aircraft survivability. Typical aircraft dry bays and engine nacelle regions contain critical components essential to the safe operation of the aircraft, such as hydraulic and fuel lines, avionics, and electrical wiring. The combination of these elements presents multiple possible fire scenarios, which fall into either accidental or intentional threats. For example, an intentional threat may consist of the rupture of a fuel tank from a ballistic impact causing a spray fire in an adjacent dry bay that critically damages the surrounding components. On the other hand, an accidental threat may consist of a fuel line leak within an engine nacelle, which ignites on the hot surface of the engine core. Fire protection within these vulnerable regions is, therefore, paramount due to the numerous fuel and ignition sources that are present. As a result of the inherently different fire scenarios, different suppression systems are often employed for each region, each of which requires a system capable of reacting effectively and efficiently to the presence of a fire. While passive technologies are often employed in dry bay protection systems, active halon suppression systems are often used in engine nacelle regions. In both scenarios, it has been determined that the overall protection benefit of increasing the effectiveness and efficiency of these systems far outweighs the cost of the system. The production ban on halogenated agents and the relative inefficiency of replacement agents further increases the need for a technology which can increase the overall system efficiency of both types of systems. Therefore, the need arises for a smart fluid delivery nozzle system which would increase the delivery mechanism of both active and passive fire protection systems, allowing not only the retrofit of current systems, but integration in the design of future systems as well.
For the past several decades, halogenated agents, notably halon 1301, have protected aircraft engine nacelles and some dry bays regions. Since the production ban on halon, scientists and engineers in the public and private sectors have been working on replacement agents and new technologies that attempt to achieve the efficiency of halon agents. For instance, innovative passive fire suppression technologies are being implemented into dry bay areas as an alternative to legacy halon systems, while the chemical industry is attempting to increase the efficiency of new halon replacement agents. Thus far, none of the systems or agents has succeeded completely in achieving the desired efficiency. All of the current technologies (passive or active) and new suppressants that have been deemed acceptable, when based on environmental friendliness, toxicity, materials compatibility, etc., lack fire-suppression efficiency as measured by weight and/or volume. To improve the fire-suppression efficiency of the candidate agents and technologies, one area of focus is suppressant distribution. For example, legacy halon 1301 systems were so effective (due to the supreme efficiency of halon 1301), research into understanding the suppressant delivery, especially in highly cluttered regions, offered little payoff. However, new replacement agents are less effective than halon 1301, making suppressant transport a more critical issue. Even the new innovative passive technologies are less effective compared to the legacy systems that they are attempting to replace. In fact, most suppression systems (active and passive) do not incorporate discharge nozzles at all, but rather simply dump suppressant in a very inefficient manner. With the lack of efficiencies in candidate technologies, increasing the agent delivery efficiency can have a large payoff in reducing the design time and/or weight of a fire protection system.
Over the last 10 years, the fire protection industry has been trying to move away from total flooding suppression systems toward systems with directed agent delivery as a method to increase system efficiency and reduce collateral damage. For instance, the US Navy has shifted from full-flooding systems for shipboard applications, to a highly directed water delivery system for their next generation fleet. These newer systems incorporate computer controlled telerobotic nozzles to direct agent at the fire region. This telerobotic nozzle technology is on the forefront of the fire protection industry. However, shipboard applications have minimal concerns with the weight of fire suppression systems. As such, such telerobotic nozzle systems are bulky and too heavy for consideration for aircraft platforms.
Aircraft platforms require fire protection systems optimized with minimal size and weight. For example, engine nacelle regions, which have the highest susceptibility to aircraft fires, contain a high level of clutter (fuel lines, wire bundles, etc.) within a compact space. This clutter blocks suppressant delivery and acts as a flame holder, protecting fires from suppression systems. As a result, a directed agent delivery would be preferred for this fire region, with the nozzles optimally placed to sufficiently protect the high risk regions. However, installation of the directed agent nozzles in an engine nacelle region is difficult due to the combination clutter in a confined space. As a result, suppression nozzles in engine nacelles will likely be installed between clutter elements to achieve the most efficient agent delivery. The proposed nozzle must not only be sufficiently small in size, but ideally would remain in a fixed position as to allow installation within the cluttered engine nacelle regions. By designing the proposed technology to meet the critical criteria necessary for engine nacelles, the nozzle will offer more than acceptable performance in dry bay areas which have increased size, less clutter and are less susceptible to fires.
Therefore, the need exists for a directional nozzle capable of being installed in both new and legacy aircraft fire suppression systems, which can automatically locate the fire region and discharge suppressant directly at the fire zone and not require total flooding of the region to be protected. This nozzle must be capable of installation in a tight space requirement, with minimal weight added, but also capable of protecting larger dry bay regions. Furthermore, this technology should not rely on a specific agent to achieve its effectiveness, since replacement systems use many separate agents. To this end, the current solution of a lightweight, self-contained universal “smart” fire suppression nozzle which is capable of locating a fire region (upon activation from an existing detector system) and discharging agent directly at the fire region within 100 ms, while remaining in a fixed installation position is presented.